The present invention relates to a braking vehicle speed measuring apparatus for measuring the initial and final braking speeds of a vehicle under braking.
Known systems for measuring the initial braking speed of a vehicle during the initial braking period and the final braking speed upon completion of the braking have been such that at the beginning and end of the braking action the measure reads the vehicle speeds by means of the speedometer attached to the vehicle or alternatively the measurements are made by such means as a fifth wheel attached to the vehicle exclusively for vehicle speed measuring purposes. Another system has been proposed in which the output of a vehicle speed sensor designed to generate a number of pulses proportional to the vehicle speed is subjected to digital-to-analog conversion and then recorded in a data recorder or the like and at the same time the initial and final braking speeds are obtained from the marked beginning and end of the braking action.
However, these known systems have the disadvantages of being low in measuring accuracy, requiring the attachment to a vehicle of such large means as a fifth wheel, being unable to easily measure the braking vehicle speed of a vehicle, etc.